package cn.itcust.jdbc;

import cn.itcust.utils.JDBCUtils;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

/**
 * 事务操作
 */
public class JdbcDemo12 {
    public static void main(String[] args) {
        Connection conn = null;
        PreparedStatement pstmt1 = null;
        PreparedStatement pstmt2 = null;
        try {
            // 1. 获取连接
            conn = JDBCUtils.getConnection();
            // 开启事务
            conn.setAutoCommit(false);

            // 2. 定义sql
            // 2.1. 张三 -500
            String sql1 = "update stu set salary = salary - ? where id = ?";
            // 2.2. 李四 +500
            String sql2 = "update stu set salary = salary + ? where id = ?";
            // 3. 获取执行sql对象
            pstmt1 = conn.prepareStatement(sql1);
            pstmt2 = conn.prepareStatement(sql2);
            // 4. 设置参数
            pstmt1.setDouble(1, 500);
            pstmt1.setInt(2, 1);

            pstmt2.setDouble(1,500);
            pstmt2.setInt(2, 2);
            // 执行sql
            pstmt1.executeUpdate();
            // 手动制造异常
            int i = 3 / 0;

            pstmt2.executeUpdate();

            // 提交事务
            conn.commit();
        } catch (SQLException e) {
            try {
                if(conn != null) {
                    conn.rollback();
                }
            } catch (SQLException e1) {
                e1.printStackTrace();
            }
            e.printStackTrace();
        } finally {
            JDBCUtils.close(pstmt1, conn);
            JDBCUtils.close(pstmt2, conn);
        }
    }
}
